Circuit breaker



March 24, 1936. J. A. oBRlr-:N 2,034,327

CIRCUIT BREAKER Filed Jan. lO, 1954 4 Sheets-Sheet 2 Invenlor March 24, `1 A OBRlEN CIRCUIT BREAKER Filed Jan. lO, 1934 4 Sheets-Sheet 3 Jas A 0,51@

llomey March 24, 1936. J. A. OBRIEN 2,034,827

CIRCUIT BREAKER Filed Jan. l0, 1934 4 Sheets-Sheet 4 E l O d 55 um u. O

e e o o oFF D /gp Patented Mar. 24, 1936 UNITED STATES PATENT OFFICE 1 Claim.

This invention appertains to new and useful improvements in the general art of circuit makers and breakers, and more particularly to a novel circuit breaker which has as its principal object to provide a thermal trip mechanism which will operate under any conditions on an electrical circuit, such as an overload or short circuit, to instantaneously open the circuit.

Another important object of the present invention is to provide a circuit breaker which is enclosed in a casing and suitably sealed so that the thermal element cannot be tampered with.

Another important object of the invention is to provide a circuit breaker which is substantially fool-proof.

Still another important object of the present.

invention is to provide a switch wherein the thermal circuit breaker operates even if the switch control is retained manually in closed circuit position.

Another important object of the present invention is to provide a switch wherein indicatingr means is provided for indicating when the thermal circuit breaker has been operated.

Another important object of the present invention is to provide a switchl including a thermal circuit breaker which can be re-set by moving the switch handle from the On position to the Off position.

Various other important objects and advantages of the invention will become apparent to the reader of the following specification.

In the drawings:-

Figure 1 represents a front elevational view of the encased switch, with the handle in On position and the re-set indicator blank.

Figure 2 represents a front elevational view of the encased switch, showing the re-set indicator indicia exposed.

Figure 3 represents a longitudinal sectional view taken substantially on line 3-3 of Figure 2.

Figure 4 represents a longitudinal sectional view also taken on line 3-3 of Figure 2, but showing the thermal breaker operated.

Figure 5 represents a longitudinal sectional view through the switch mechanism, showing the switch mechanism in closed position.

Figure 6 represents' a longitudinal sectional view through the switch mechanism, showing the circuit breaker operated by the thermal element.

Figure 7 vrepresents a longitudinal sectional view through the switch mechanism, showing the switch means in circuit open position by manual control.

Figure 8 represents a side elevational view of the thermal element.

Figure 9 represents a fragmentary detailed sectional view taken substantially on line 9 9 of Figure 8. 5

Figure 10 represents an enlarged fragmentary detailed sectional view taken substantially on line IU-IU of Figure 1.

Figure 11 represents a perspective View of the trip arm. l l0 Figure 12 represents a perspective view of the carrier plate.

Figure 13 represents a perspective view of the trip throwing member.

Figure 14 represents a perspective view of the l5 swingable contact plate.

Figure 15 represents a perspective view of the trigger arm.

Figure 16 represents a perspective view of the bell crank.

Figure 17 represents a perspective view of the indicator operating arm.

Figure 18 represents a front elevational view of a modied form of switch including an indicating lamp.

Figure 19 represents a front elevational view of the switch mechanism, with the cover plate removed.

Figure 20 represents a side elevational view of the mechanism in the casing shown in Figure 19, with the thermostatic circuit breaker operated.

Figure 21 represents a perspective View of the contact arm for the indicator lamp of this modified form of the switch.

Referring to the drawings wherein like numerals designate like parts, it can be seen that numeral 5 represents the base of the switch which can be of any suitable di-electric material. Numeral 6 represents a hood for disposition over the mechanism of the-switch and this hood is provided with suitable means whereby the same can be secured to the base, but as is clearly shown in Figure 10, it is preferred that the bottom of the base 5 be provided with recesses and that screws 8 be disposed through the base and fed into the 45 edge portion of the hood 6 so that the heads of the screws will be located within the recesses. These recesses are then lled with some suitable sealing material 9 so that access cannot be had to the mechanism contained in the hood.

The hood 6 is provided with a slot ID therein through which the handle Il of the switch lever I2 can protrude, this handle Il, being o1' suitable di-electric material. The lever I2 carries a 55 curved plate I3 which always maintains the slot III closed.

In carrying out the present invention, the switch proper is of the quick-throw, spring toggle type and consists of a plate I4 having a pair of posts I5-I5 extending upwardlyfrom one end thereof,`wnile a pair of posts I6 extends upwardly from the opposite end of the plate.

Numeral I1 represents an L-shaped contact post at one end of the base 5, which aiords an obliquely disposed contact member I8 complementary to the obliquely disposed contact I9 on one end of the swingable contact plate 26. A shoulder 2I is formed by offsetting the contact I9 with respect to the plate 20 and in this shoulder 2I is the opening 22 for the latch projection 23 onthe oiset extension 24 of the trip arm 25 at the opposite end of which a longitudinally extending slot 26 is provided.

The swingable contact plate 20 is provided with a pair of laterally extending lugs 21--21 projecting from opposite edges of the plate adjacent the shoulder 2I and each is provided with an opening 28 therein for receiving one end of a spring, only one spring being shown in the drawings and this is denoted lby numeral 29. The spring connects at one end to the corresponding lug 21 and at its opposite end to the 1ug36 protruding from the plate I4. (See Figure 4.)

A pair of upstanding ears 3I-3I is provided at the remaining end o f the plate 20 and these have openings 32 therein through which the pin 33 extends, this pin 33 extending through the posts I6 and also through the openings 34 inthe ears 35-35 at one end of the aforementioned carrier plate, generally referred to by numeral 36. Thus the carrier plate 36 and the swingable contact plate 20 are carried by the aforementioned pin 33. The adjacent end of the carrier plate 36 is slotted, as at 31, to receive the inner end of the trigger arm 38 and apertured ears 39 at this end of the carrier plate 36 support a pin which also extends through the opening 40 at the inner end of the arm 38 so that the arm 38 is swingably carried by the carrier plate 36. It will also be observed that the corresponding end of the contact plate 20 has a cut-out, denoted by numeral 4I, for accommodating the action of the slotted end of the carrier plate 36. ,i

As is clearly shown in Figures 5, 6 and ,7, a short strip spring 42 is carried by the bottom of the carrier plate 36 and this tensionally bears against the toe 43 at the pivotal end of the trigger arm 38 so as tonormally throw the same tensionally against the trip arm 25 at the outer vend of the slot 26 through which the same operates. It will also be observed that the trigger arm 38 has a shoulder 44 at an intermediate point under which the free end of the trip arm 25 can engage, and also a laterally disposed head 45 at its free end which is located within the path of the insulated head pieceA 46 on the outer end of the U-shaped bi-metal thermal 'element 41. The leg portions of this thermal element have feet 48-49, one of which is connected to the binding post 56, while the other is connected by the jumper 5I to the adjacent end of the carrier plate 36. `(See Figure 4.)

The other end of the carrier plate 36 is provided with a pair of upstanding hook-shaped members 52 bridged by a member 53. As is clearly shown in Figure 4,' the `extension 24 of thetrip arm 25 extends through the space between the bridge piece 53 and the adjacent end of the carrier plate 36.

2,034,827 v- Y 'e The trip `throwing member is denoted by numeral 54 and is a channel iron shaped structure having registering openings 55 in its side anges and a pair of oppositely directed leg members 56 at its opposite end. A portion of the anges of the member are free and provided with openings 51. The oisetting portion 58 of the .trip arm. 25 is seatable between the free iiange portions and the openings in the offset portion 58 will'receive a pin 58 which also extends through the openings in the trip throwing member 54.

' A leaf spring (clearly shown in Figure 6) is denoted by numeral 59 and is anchored at one end to the carrier plate 36, while its free end impinges against the opposite side of the trip throwing member 54.

The bell crank 60 is swin`gably connected to one of the posts I5 by its heel a, this bell crank 60 being provided at one end with the T-head 6I which fits through the longitudinally extending slot 62 in the free end of the switch lever I2, this switch lever I2 being swingably supported at 63. The coiled extensible spring 64 is interposed between the remaining end of the crank 60 and one of the legs 56 of the trip throwing member 54.

Mounted upon one of the posts I6 is the indicating shutter 65, the same being provided with an arm 66 pivotally connected, as at 61, to the post. Numeral 68 represents an elongated indicator operatingarm pivotally connected, as at 69, to the intermediate portion of the arm 66 and provided with a notch 10 at an intermediate point capable of receiving the pintle 1I which projects inwardly from one leg of the switch lever I2. The arm 63, at its free end, is provided with a downturned foot member 12 located within the path of the upwardly swingable trip arm 25. The coiled spring 13 is interposed between the foot end of the arm 68 and one of the posts I6.

By referring to Figures 1 and 2, it can be seen that the hood 6 is provided with a small peep opening 14 therein through which the indicator shutter is visible.

It can now be seen that when the switch is manually operated, the entire thermal breaker mechanism, involving the elements in Figures 11, l2, 13, 14, 15 and 17, remain intact in the compact position, as shown in Figure 3, and simply rock with the toggle action of the switch in conjunction with the bell crank 60. For example, when the switch is in closed circuit position, the parts will be as represented in Figure 3, while when the switch is manually in open circuit position, the mechanism will be as shown in Figure 7. However, when vthere is an overload or a short circuit and the thermal element 41 fiexes so as to press its head 46 against the offset4 head 45 on the trigger arm 38, the arm 38 is moved inwardly toward the mechanism, thus moving the shoulder 44 of the trigger arm away from over the trip arm 25. 'I'he tension of the spring 59 now throws the trip throwing member 54 upwardly and this action rocks the trip arm 25 slightly so that the latch 23 is disengaged from the opening 22 in the contact plate 26, thus freeing the contact plate 28 so that the spring 29 will pull the same downwardly to the open circuit position shown in Figure 4. The trip arm 25 will continue upwardly and strike against the foot 12 of the indicator operating arm 68, resulting in the disengagement of this arm 68 from the pintle 1I so that the spring 13 can pull the arm over the ,pin to the position shown in Figure 6,

thus displaying the word "Re-set through the sight opening 'I4 in the hood 8.

By simply moving the lever l2 from the On to the Oi position, a downward pull is exerted by the spring 13 on the trip throwing member 54 which snaps the trip arm 25 downwardly so' l figuration therein and this is denoted by numeral 14a behind which may be placed a suitable light diffusing glass or the like. This opening 14al is over the compartment B which is separated from the mechanism compartment by the partition C. In the compartment B is a lamp 80, one side of which is connected by the jumper 8| to one side of the line 82. The other side of the line is oonnected through the switch mechanism by way of the thermostatic element 41. An additional binding post 83 is provided on the base 5 and from this extends the jumper I4 to connect to the opposite side of the lamp 80. In addition to the lamp and its electrical connections above described, a contact, such as is shown in Figure 21, is employed in lieu of the indicator operating arm shown in Figure 17 and the indicator element 65 of the preferred form of the invention.

The contact shown in Figure 21 consists of the small base plate 85 secured first by the binding post 83 and from this extends an upstanding post 86. Extending laterally from this post 86 is the arm B1 and at its free end is a depending inclined spring contact member $8 located within the path of the trip arm 25. Obviously, when the trip arm goes up as a result of the releasement of the thermal circuit breaker mechanism and strikes the contact B8, while the contacts I 8|9 separate, current will be taken off of the line side of the switch and supplied to the lamp 80 so as to indicate that the thermal breaker has operated.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size and materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

Having described the claimed as new isz- A switch of the class described, comprising a base, a pair of spaced upstanding posts, a second pair of upstanding posts spaced from said first named posts, and obliquely disposed stationary electrical contact on said base, a swingable plate pivotally mounted at one end to said second named posts and having an electrical contact thereon adapted to cooperate with the stationary electrical contact in opening and closing an electrical circuit, resilient means normally urging the plate in a direction to open the electrical contacts. a switch arm for maintaining the plate in a position for opening said electrical contact, a resilient trigger arm for actuating said switch arm, a thermal element for actuating said trigger arm, and means pivotally mounted on said rst named posts for manually actuating said swingable plate.

invention, what is JOSEPH A. OBRIEN. 

